I am about to print a project from a single frame dslr. I need to achieve maximum size, approx 2.4 metres across. I have the advantage that the print won't be looked at any closer than 3.5 metres.

I would love some help upsizing the image file for maximum size and quality. I am aware of the "perfect resize" program but have been advised that the newer versions of photoshop (I have CS5) are just as good. I do not have access to the original raw file and am working from a high quality tiff.

Any advise on "best practice" for achieving maximum quality results from this project would be appreciated.

Get the file as clean as possible. I don't mean just reduce the noise but also avoid processing artifacts like halos from over-sharpening. Print through Q-Image Ultimate. Or at least use Q-Image to upsize and output a file that you then print through the pipeline that you are accustomed to.

I am about to print a project from a single frame dslr. I need to achieve maximum size, approx 2.4 metres across. I have the advantage that the print won't be looked at any closer than 3.5 metres.

Hi,

That should not be a big problem, especially from that distance, provided that the image is of good quality to begin with.

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I would love some help upsizing the image file for maximum size and quality. I am aware of the "perfect resize" program but have been advised that the newer versions of photoshop (I have CS5) are just as good.

That's not correct. The dated upsampling routines of Photoshop are pretty poor, especially when compared to more modern (adaptive) methods. The quality of "Perfect Resize" is a bit questionable IMHO, it tends to produce a more posterized look than some of the alternatives.

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I do not have access to the original raw file and am working from a high quality tiff.

That's a real pitty, because many Raw conversions have too much sharpening already, and enlarging the file size will also enlarge the sharpening artifacts. The best originals for upsampling have only Capture sharpening applied, and if further sharpening was done it hopefully didn't produce ugly halos.

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Any advise on "best practice" for achieving maximum quality results from this project would be appreciated.

Three additional things need to be known before good advise can be given; The type of image content (e.g. modern archtecture, or a busy landscape, or etc.), the current file size in pixels (width x height), and on which printer is it going to be printed. The first might dictate a preferred algorithm to use instead of a generic one, and the others will determine the amount of upsampling required which may further point in the direction of a specific upsampling algorithm or settings.

What could also be helpful for you, is to post a crop from the image and let us do our magic on it, and then you can have it printed for comparison at the minimum viewing distance you mentioned. For that the required amount of upsampling should be known, otherwise you will get all sorts of different sizes to work from, and the crop size will also be easier to determine.

FWIW Alien Skin Blow Up does a pretty good job with images that have been damaged by too much sharpening, that's its strongest point. Worth taking a quick look at the free trial if you have such a file.

Last testing I did upsizing for a Webinar I did, I found Lightroom with proper capture sharpening did a significantly better job (evaluate on a print, critical) than Perfect Resize. Photoshop was a close 2nd, again due to proper handling of the data in terms of capture sharpening. Read the Schewe article and save your money on 3rd party upsizing products. If you do test, be sure to always output a sample to size on a small print. Examine at viewing distance then put your nose up to the print. I think you'll find you don't need any 3rd party products at all, Photoshop (or Lightroom) will do just as good and in most cases better job assuming you handle the entire process correctly.

The one advantage some third party upsizers have is that they recast the image from a pixel-based format to a vector, fractal, or spline equivalent. For mural sized blow ups you can replace giant, stair-stepped pixels with larger, smooth edged geometric shapes that are at least cleaner looking. The image starts to look like it's made of larger brush strokes, rather than piles of smaller, grungy pixels. The pixellated version might still look sharper from a distance, but the resizer version will look more sanitary, somehow. For murals that might be viewed close up, that's sometimes a good thing.

But for normal print sizes, the specialized resizers aren't much use, except possibly for toning down over processing artifacts in intermediate files when the camera originals aren't available.

I guess. Only if the output from the sizing is better than what you'd get elsewhere and my testing didn't show that with the couple products I played with.

I compared uprezzing to 17x22 print from 16MP sensor file (about 180%) and found stairstepping on diagonals in LR4 that was not present from Genuine Fractals 6 (precursor to Perfect Resize) or Photozoom. This was looking at the actual prints. So the thing to do is to try out the free demos and decide for yourself.

Three additional things need to be known before good advise can be given; The type of image content (e.g. modern archtecture, or a busy landscape, or etc.), the current file size in pixels (width x height), and on which printer is it going to be printed. The first might dictate a preferred algorithm to use instead of a generic one, and the others will determine the amount of upsampling required which may further point in the direction of a specific upsampling algorithm or settings.

Ok image file size is 3240 x 2160

The image is of a wave breaking, pin sharp water shot, non regimented lines.

Three additional things need to be known before good advise can be given; The type of image content (e.g. modern archtecture, or a busy landscape, or etc.), the current file size in pixels (width x height), and on which printer is it going to be printed. The first might dictate a preferred algorithm to use instead of a generic one, and the others will determine the amount of upsampling required which may further point in the direction of a specific upsampling algorithm or settings.

Ok image file size is 3240 x 2160

The image is of a wave breaking, pin sharp water shot, non regimented lines.

Printer is a 9880 epson.

Thanks for all the input crew.

Okay, so we need to go from 3240 pixels to 2.4 metres @ 360 PPI = 34016 pixels. Lower PPI settings will cause the printer driver to upsample to 360 PPI, with an algorithm that's probably more geared towards speed than accuracy (because the processing power isn't there in the printer's hardware). That is a magnification of 10.5x. That also means that any artifacts that the interpolation algorithms introduce will become quite visible, because the interpolation will usually not create resolution, but just smooth transitions between existing pixel values. Therefore artifacts will stick out like a sore thumb against expected smooth transitions. Human vision is quite good at spotting anomalities that do not follow the expected pattern.

'Fortunately' there will be many more interpolated pixels than original pixels, so the artifacts will also be a bit fuzzy.

Here is a crop of 300 x 300 px, hopefully with enough different types of detail and slanted edges to reveal shortcomings from resampling. It was upsampled to 3150 x 3150 px, the same magnification a full sized image would undergo, given the above criteria:

Attached are 3 upsampled versions:1. A Photoshop 6 upsample with BiCubic resampling.2. A Lightroom 4 upsample, presumably using BiCubic Smoother (and virtually indistinguishable from a PS Bicubic Smoother resampling).3. A PhotoZoom Pro upsample, Sharpness dialled down to 10% instead of 100%, and an amount of 30 grain added.No specific output sharpening was applied to any of the files.

When printed at 360 PPI and viewed from 3.5 metres, the differences (and the artifacts) will probably be hard to see, but from a bit closer there is a distinct different in acutance.

I'll second using Qimage Ultimate.no guesswork, just give it your needed size and the program does the rest, I've been getting outstanding results printing really crappy (small files), on my 7900 and 9890 to pretty big sizes, for customers.get a free trial and do a test.

Of course, Qimage (Ultimate) has always done (large format) output well. Attached a 'Fusion' interpolated version, also without output sharpening (to allow direct comparison with the others). It is slightly more detailed than Lightroom / Photoshop Bicubic Smoother, but more practical in use (due to the output size required, which often won't fit a single roll width).

Of course all these programs can add their own flavor of output sharpening, but it will usually be based on the upsampled data as was attached in these posts.